Tone arm control mechanism for phonographs



June 3, 1941.

0. A. HOKANSON TONE ARM CONTROL MECHANISM FOR PHONOGRAPHS 2 Sheets-Sheet 1 Original Filed 001. 16, 1937 \NVENTOR H BY Y 4 ATTORNEY June 3,1941. 0. A. HoKA-NsQN- 2, 7

TONE ARM CONTROL MECHANISM FOR PHONQGRAFHS Original Filed Oct. '16. 1937 2: Sheets-Sheet 2 INVENTOR ATTORNEY Patented June 3,19%

v UNITED TONE ABM CONTRGL MECHANISM FOR PHONOGRAPHS Otto A. Holranson, Snyder, hi. Y., assignor to The Rudolph Wurlitzer Company, North Tonawanda, N. Y., a corporation of Ohio Original application October 16, 1937, Serial No.

Divided and this application October 18, 1939, Serial No. acacia g (c1. ova-415) This invention relates to new and useful improvements in automatic selective phonographs but more particularly to a mechanism for controlling the tone arms thereof.

'It has for one of its objects to provide a tone arm trip mechanism which is so designed as to be edectually actuated upon an abnormal swing of the tone arm, as when shifting the tone arm by hand to a tripping position, and also when the needle of the tone arm encounters the terminal groove of the record.

Another object of the invention is to provide a tone armtrip mechanism which is so designed as to reliably and positively efiect an automatic adjustment to a predetermined position, both vertically and horizontally for playing engagement with the record as well as to eflect the restoratlon of the tone arm to its initial non-play position at one side of the turntable after a record has been played.

A further object of the invention is to provide a tone a'rm trip mechanism which is simple, compact and inexpensive in construction, reliable in operation, and whose parts are not liable to get out of order.

This invention is a division of my copending application Serial No. 169,442, filed October 16, 1937.

Other features of the invention reside in the construction and arrangement of parts hereinafter described and particularly pointed out in the appended claims.

In the accompanying drawings:

Figure 1 is an elevational view of an automatic selective phonograph showing my improved tone arm trip mechanism associated therewith. Figure 2 is a side elevation, partly in section, of the tone arm and associated parts. Figure 3 is a front elevation, partly in section, of the tone arm and its associated par-ts, the tone arm being in its non-play position. Figure 4 is a vertical sectional View of the tone arm and associated parts, with the tone arm in its non-play position. Figure 5 is a horizontal section taken on line 5-5, Figure 2.

Similar characters of reierence indicate corresponding parts throughout the several views. 4

My improved tone arm trip mechanism has been shown, by way of example, in connection with an automatic phonograph oi the type shown in the United States Patent No. 2,096,718 granted October 26, 1937, wherein the numeral Ill indicates the supporting frame, II the tone arm mounted to swing both vertically and horizontally for movement into and out of playing engagement with the records, and I2 indicates the turntable which is adapted to support the records in stack-like fashion for selective play and which is adjustable to various heights to properly position a record in the operating plane of the tone arm, after which the record-stack is split above the record selected for play to provide an operating clearance for the tone arm.

In the preferred construction of the tone arm trip mechanism shown in the drawings, it con-' sists of an upright supporting post or column it about which the tone arm revolves in a definite horizontal plane, the tone arm it being pivoted to swing vertically about a pivot it applied to the yoke portion of an upright stem l5 journaled in a step bearing l6 of the post 23, this vertical swinging of the tone arm being necessary in bringing its reproducing needle ll into engagement with a record for play or out of engagement therewith when swinging outwardly over the record after play. Also fulcrumed on the pivot it is a laterally-swinging depending brace or stay bar it which moves with the tone arm and which is provided at its lower end with an adjusting screw it in contact at its inner end with a laterally-swinging pendant back plate or yoke 20 disposed alongside the post It and pivoted at 2! to the upper endof the latter as shown in Figures 2 and 4. Mounted on the post adjoining this pendant back plate to turn thereon, is a cam member or sleeve 22 which rides against the inner face of this back plate and thereby causes the latter to swing in a direction away trom or toward the post to in turn efiect, through the medium of the stay bar 18, the raising or lowering of the tone arm out of or into engagement with the record. In the non-play or outwardlyswung position of the tone arm, shown in Figure a, the cam member 22 is abutting the back plate to support the tone arm in its elevated position. Depending from the upper or yoke portion of the tone arm stem l5 in'adjoining relation to the stay bar it is a substantially L-shaped bar 23 which likewise moves with the tone. arm and against the lower end of which a substantially radial lug ll-projecting from the cam member 22 is adapted to'a-but, so that when motion is transmitted to this cam member, its lug 2i encounters the horizontal portion of the L-shaped bar 23 and causes the tone arm to swing out-.

wardly to its initial non-play position after a given record has been played.

The numeral 25 indicates a link adapted to be actuated in one direction or the other at predetermined times in the cycle of operation 01 the record-changing mechanism as clearly shown in my aforesaid parent application Serial No. 169,442, such link being connected to a depending radial lug 26 projecting from the cam member 22 so that when such link is actuated in one direction it turns the cam member in a clockwise dimotion for adjusting the tone arm into playing engagement with the record, and when such 11111: is actuated in the opposite direction it turns the cam member in.a counter-clockwise direction for adiustably governing the movements of thetone arm II to its initial or non-play position at one side of the turntable. When the record has completed its play, then motion is transmitted to the linl: causing the tone arm post cam member 22 to swing in a counter-clockwise direction, thereby rocking the pendant back plate so outwardly, elevating the tone arm from engagement with the record and ultimately swinging the tone arm outwardly to a position clear of the record stack and at-one side of the turntable, this position' of the parts being shown in Figure 4 and by-dotted lines in Figure 5. The tone'arm is held in this outwardly-swung position until another record has been selected and set in position for play, at which time the tone arm post cam member 22 is turned in a clockwise direction to cause its radial lug 24 to recede from the bar 28 and allow the tone arm to swing inwardly.

To compel the tone arm to swing inwardly into playing engagement with the record, I provide a horizontally-swinging arm as pivoted on a stationary plate 29 projecting from the lower end of the tone arm supporting post is and arranged to abut at its free end against the horizontal portion 01 the L-shaped bar 23, a

spring 30 connected to this arm tending constantly to urge the bar and the tone arm 5 l associated therewith to an inwardly-swung posi-= tion. By this construction, as the lug 26 on the cam member 22 recedes from the bar 23, the spring-urged arm 28 compels the tone arm to swing inwardly.

In swinging from non-play to play position the tone arm is heldelevated bythe back plate 20 and cam member 22 until such time as the needle oi the tone arm is immediately over the starting portion of the sound groove of the record. This position of the tone arm is governed byra gravity-actuated pawl 3i applied to a plate 32 secured to the upper portion of thestay bar i8 and adapted in the cam-engaging position 01' the hack plate 263, that is, in a position supporting the tone arm in its elevated position, to abut against a stop shoulder 33 formed in the upper edge of the back plate 29,

' so that when the tone arm, during its initial inward swing, reaches a position over the starting groove of the record it is arrested by such pawl engaging its companion shoulder. As previously stated, during the inward swing of the tone arm, the cam member 22 i swung in a direction to move its arm 24 away from the adjoining portion of the pendant bar 23 to allow the spring-actuated arm 28 to swing the tone arm inwardly. After the tone arm is arrested in this manner, the continued turning of the cam member 22 causes it to eventually ride 0E or be removed from supporting engagement with the pendant back plate 20 and allows the tone arm to swing downward by gravity to bring its needle into playing engagement with the record groove. As the back plate rides ed the cam member 22 and swings inwardly,-its upper edge bearing the pawl-engaging shoulder St is lowered, thereby disengaging ranch shoulder from the pawl to allow the free inward swing of the tone arm during ple of the record and in this position of the parts said pawl is supported at its free end on a flange ti l projecting inwardly from the lower edge of the pawbhearing plate When the playing of a recordis completed, the tone arm serves to antomatlikillr net the record-cg mechanism of the phonograph in motion to restore the record stack to its original position in reess to efiect the selection of the next record. For this purpose I provide a vertically-swinging trip lever 35: pivoted at 36 'to the plate 29, the outer arm of this lever being provided in its top edge with a series of teeth ll termnating in an inclined portion or tall 88. Arranged for cooperation with this trip lever and particularly with the teeth and inclined por tion thereof is a pendant pawl'flt supported on a pin to projecting from the horizontal portion of the L-shaped lever 23 which moves with the tone arm. The other arm of this trip lever 36 is provided in its lower edge with a latching shoulder ti against which oneend or a horizon tally-swinging lever is adapted to engage. A spring i l normally urges the trip lever into its latched position. 'lhis trip lever when actuated, at the end of play ora record, as when the stylus encounters the eccentric or spiral lead in type groove, releases the horizontally swinn ing lever ll from the shoulder fit to initiate and render the record-chom ing mechanism of the phonograph operative, in the manner set forth in my parent application Serial No ldilndz, to restore the tone arm to its initial non play position. During its restoring movement the tone arm is first lifted vertically to bring its stylus clear of the record and then swung horizontally outwardly to a position at one side oi the turntable.

I claim as my invention:

1;. In an automatic phonograph, a turntable for carrying a record dish, a reproducing meow including a tone arm, en upright post on which said tone arm is mounted to swing horizontally and pivoted to swing vertically into and out of playing engagement with a record, a brace penoling from the tone arm forwardly oi its pivot, a rotatable cam member for actuating said brace to control at a predetermined time the verticalpivoting of the tone arm and the horizontal swinging of the tone arm, and means adapted for movement in one direction or the other and connected to said cam member for turning it in one direction for elevating the tone arm out of engagement with the played record and swing ing it to non-play position. and for turning it in the opposite direction for swinging the tone arm inwardly and downwardly for playing cn= gagement with the nent'recorol.

2. In an automatic phonograph, a turntable for cag a record dish, a reproducing means including a tone arm, an upright post on which said tone is mounted to some horizontally and pivoted to swing vertically into and out oi playing engagement with a. record, a lorace pend ing from the tone arm forwardly of its pivot, a rotatable cam member for actuating said brace to control at a predetermined time the vertical= pivoting oi the tone arm and the horizontal swinging oi the tone arm, means adapted for movement in one direction or the other and connected to said cam member for turning it in one direction for'elevailng the tone arm out of engagement with the played record andswing ing it to non-play position, and for turning it in the opposite direction for swinging the tone arm inwardly and downwardly for playing engagement with the next record, and companion interengaging means applied to the tone arm post and said brace for releasably retaining the tone arm in its elevated position when swinging from non-play to play position until immediately over of the tone arm, releasable stop means operatively associated with the tone arm post and said brace for limiting the inward swing of the tone arm, while elevated, from non-play position to a position immediately over the starting groove of the record to be played, and means controlled by the cam of said rotatable means for automatical- 1y releasing said stop means at a predetermined time to permit the normal playing movement of the tone arm.

4. In an automatic phonograph, a turntable for carrying a record disk, a. reproducing means including a tone arm, a post on which said tone arm is mounted to swing horizontally and pivoted to swing vertically into and out or playing engagement with a record, a brace depending from the tone arm forwardly of its pivot, a yoke member pivoted to said post and engageable with said brace for shifting it to raise or lower the tone arm, rotatable means for controlling the horizontal swinging of the tone arm to and from play position and including a cam in bearing contact with said yoke member for actuating the same to control at a predetermined time the vertical pivoting of the tone arm, said yoke member having a stop shoulder thereon, and a latch element applied to said brace and engageable with said stop shoulder at a predetermined time for arresting the inward swing of the tone arm, while elevated, to a position immediately over the starting groove of the record to be played, said latch element being released from said'yoke member shoulder upon the lowering of the cam-controlled yoke member to bring the tone arm into playing engagement with the record. I

5. A tone arm mounting for automatic phonographs, comprising, a post on which the tone arm is mounted to swing horizontally and pivoted to swing vertically into and out of playing engagement with a record, a brace depending from the tone arm forwardly of its pivot, a rotatable member mounted on said post for controlling the movements of the tone arm and including a cam, a vertically-displaceable yoke pivoted to said post between said brace and said rotatable member for actuation by said cam to control the vertical movements of the tone arm, said yoke having a stop "shoulder thereon, and a pawl mounted on said tone arm brace for releasable'engagement with said yoke-shoulder for limiting the inward swing of the tone arm, while elevated, to a posi-' tion immediately over the starting groove of the record to be played.

6. A tone arm mounting for automatic phonographs, comprising a post on which the tone arm is mounted to swing horizontally and pivoted to swing vertically into and out of playing engagement with a recorcLa brace depending from the tone arm forwardly of its pivot, a rotatable member mounted on said post for movement in one direction or the other for controlling the movements of the tone arm and including a cam, a vertically-displaceable yoke pivoted to said post between said brace and said rotatable member for actuation by said cam to control the vertical movements of the tone arm, a bar depending from the tone arm for operative coupling engagement with said rotatable member to swing the tone arm outwardly from the end of its playing position to non-play position, means engageable with said bar for yieldingly urging it in a direction to swing the tone arm inwardly from non-play position to a position for playing a record as the rotatable member is motivated in the opposite direction, and releasable latch means operatively associated with said brace and said yoke for limiting the inward swing of the tone arm, while elevated, to a position immediately over the starting groove of the record to be played.

OTTO A. HOKANSON. 

